The Bioreactor is a biological engineering technology began in 1980s, and refers to any manufacturing device or engineering device for providing biological activity environment. The bioreactors are devices or systems use biological functions of bio-organisms, to obtain target products, cells, tissues and organs, etc. by biochemical reaction or biological metabolism in vitro or in vivo, and are reactors related to biological or biochemical active material production out of the reaction process by specific biological. These bioreactors generally in cylindrical shape and the volume ranges of from a few liters to several cubic meters, and generally made up of stainless steel.
The bioreactor technology has gone through three stages: bacterial bioreactors, cell bioreactors and transgenic bioreactor. The transgenic bioreactors are divided in transgenic animal bioreactors and transgenic plant bioreactors. The transgenic plant bioreactors are mostly configured for improving plant varieties. The transgenic animal bioreactors are configured for improving animal varieties, while often configured for producing high value-added pharmaceutical products and protein nowadays.
In application of water treatment, the bioreactor is mainly membrane bioreactor (MBR). Membrane bioreactor is a sewage treatment and reuse technology combined with biodegradable effect and efficient membrane separation technology. Membrane bioreactor commonly employs organic film, common film material is polyethylene, polypropylene, etc., hollow fiber membranes and flat membranes are employed to make micro-filtration membrane, ultrafiltration membranes and reverse osmosis membranes and the like. A monomer membrane bioreactor is generally tubular-structured, and mainly consists of two parts of membrane separation module and biological reactor. In use, a number of monomer membrane bioreactors are connected in series or in parallel, or a combination of both, to form a system, activated sludge and macromolecules in the biochemical reaction tank of a sewage treatment plant are entrapped by using of a membrane separation device, a secondary sedimentation tank is eliminated. The Membrane bioreactor is actually a general term for three reactors: (1) aeration membrane bioreactor (AMBR); (2) extractive membrane bioreactor (EMBR); (3) solid-liquid separation membrane bioreactor (SLSMBR). Compared with some traditional biological treatment processes, the membrane bioreactor has major advantages of higher effluent quality and stability, less excess sludge, small floor space, and higher removal efficiency of ammonia nitrogen and refractory organics, however, on the other hand, the membrane bioreactor also has major disadvantages of higher cost, membrane fouling and membrane plugging, inconvenience for operation and management, higher energy consumption, and higher maintenance cost. Thus, the membrane bioreactor is generally used in sewage treatment plants which has high requirement on effluent quality, and less sewage to be treated, such as sewage user's daily sewage treatment, reuse of remote living quarters, hotels, resorts, schools, offices and other decentralized organic which are difficult to be collected by municipal sewage pipe network, and organic sewage treatment of industries of beer, leather, food and chemical, etc. The defects of the membrane bioreactor induced that it is difficult to popularly apply to large-scale sewage treatment plants.
Up to now, traditional sewage treatment technologies either consume large amount of energy source, or occupy large area. The traditional treatment process becomes a heavy burden.
In addition, the cleanliness of drinking water directly affects the health of the general public. The existing main problem of drinking water in high oxygen consumption. High oxygen consumption means that too much organic matters involved in drinking water. Under current technical conditions, removing the organic matters is generally by putting chlorine into the water for water purification. But the water disinfection will increase by-products which can increase mutagenic activity of water, thus having a long-term negative impact on human health. Features of harm of the organic matters on health often are lagging. It often taken 20˜30 years from harm being done on human health by the organic matters to human being found sick. For sewage treatment, one fundamental drawback of the traditional processing method is utilizing equipment with high energy consumption to resist potential energy and resources in the water. In traditional aerobic biological treatment processes, contaminants may volatilize easily along with the aeration air flow, gas stripping phenomenon occurs, so that not only the treatment effect is very unstable, but also cause air pollution. Adding oxygen using physical methods, flocculation and sedimentation using chemical methods, biological anaerobic reaction or aerobic reaction method are used to treat one cubic meter of sewage will result in a very high energy consumption. Statistical data showing that, in the United States 7% to 8% of the electricity are consumed by 25,000 sewage treatment plants and 18,000 sewage sludge treatment facilities. If wastewater is treated according to the American model, China is expected to build 4.5 sewage treatment plants and 30,000 sewage sludge treatment plants up to 2040 following the current process of urbanization. At that time, energy consumption on sewage treatment will become a heavy burden. A new small wetland wastewater treatment technology with relatively low energy consumption is spread at China's villages and towns. However, this technology encountered greater resistance due to large occupied area and limited decontamination capacity.
Drinking water purification and sewage treatment have problems in four areas:
1) Huge energy consumption resulting in unsustainability;
2) Even if all of the processing in accordance with the requirements of discharge standards, diluted ecological water no longer exists;
3) The high cost of wastewater treatment become a lifelong burden on the general public.
4) Purification and treatment taking up a lot of land but not to create economic wealth, squeezing the living space.